Substrate Processing Liquid Supply Timing Control
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Solution Overview
Problem
During semiconductor device manufacturing, processing liquids used for cleaning the top surface of a substrate can contaminate the bottom surface due to splashing or mist, leading to contamination of the device formation surface.
Innovation Solution
A substrate processing apparatus is designed with separate supply devices for the top and bottom surfaces, along with a control unit that manages the liquid supply to prevent contamination by stopping the liquid supply to the bottom surface after the top surface has been cleaned, utilizing a brush with an outwardly bent cleaning body to minimize mist generation and a substrate holding mechanism that maintains the substrate at a distance from the base plate to reduce splashing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If processing liquid is supplied onto the top surface of the substrate for cleaning, then the top surface cleaning effectiveness is improved, but the bottom surface becomes contaminated by splashing or mist of the processing liquid
Solution Approach 1:
The substrate processing apparatus divides the liquid supply function into separate first and second liquid supply devices, one for the top surface and another for the bottom surface. This segmentation allows independent control of liquid supply to each surface, preventing cross-contamination while maintaining effective cleaning on both surfaces
Solution Approach 2:
The control unit stops the supply of processing liquid to the top surface before stopping the supply to the bottom surface. This preliminary action ensures that any remaining liquid on the top surface is removed by centrifugal force during substrate rotation before the bottom surface supply ceases, preventing contamination transfer
2Manufacturing precision
If a brush is brought into contact with the top surface of the substrate for physical cleaning, then the top surface cleaning effectiveness is improved, but processing liquid and mist are generated that can contaminate the bottom surface
Solution Approach 1:
The apparatus utilizes the centrifugal force generated by substrate rotation to remove processing liquid and mist from the top surface. By timing the cessation of top surface liquid supply appropriately before bottom surface supply stops, the system converts the potentially harmful centrifugal force that could spread contamination into a beneficial mechanism that removes contaminants from the top surface before they can reach the bottom surface
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively suppresses contamination of the bottom surface by ensuring that any remaining processing liquid is removed from the top surface through centrifugal force before stopping the supply to the bottom surface, thereby preventing liquid from adhering and causing contamination.
Implementation Method 1
ensuring that any remaining processing liquid is removed from the top surface through centrifugal force before stopping the supply to the bottom surface
Data Source
AI summary
Contamination of a bottom surface of a substrate caused by a processing liquid used for cleaning a top surface of the substrate can be suppressed. After performing a liquid processing on the top surface of the substrate and a liquid processing on the bottom surface of the substrate in parallel while rotating the substrate by a substrate holding/rotating unit, when stopping the liquid processing on the top surface of the substrate and the liquid processing on the bottom surface of the substrate, a control unit 18 stops a supply of the processing liquid onto the top surface of the substrate by a first processing liquid supply device 73, and then, stops a supply of the processing liquid onto the bottom surface of the substrate by a second processing liquid supply device 71.